Lath



March 20, 1945. e. A. BUTTRESS LATH Filed June 22. 1943 avvucwvlkw Geozgga A. 13a zfress:

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Patented Mar. 20,1945.

STATES O i E Y LATHE George A... B.uttress, Iaos Angeles, assignor of; one-halt toR. S..Berry, AngelejsaGalm Application-June 22, 1943; serial ze). 491,846 l Thisinrention relates to lath. board and more holes will have a. frusto-conical. shape so as to effect a keyed or dove-tailed bondfwith the plaster applied therein and inwhi'ch. the enlargedinner ends of the holes are partly'but not wholely-covered by the backing sheet so that while permitting; a. portion of the applied plaster. to pass. to the back of the board will ofier such resistance to this passage of; the plaster as. to, minimize. the. discharge of excess plaster through} the board. This. construction is designed to. conserve plaster.

' and also to effect a substantial bondbetweenthe plaster and the board.

'1 An object ofjthe invention is to. provide a meansand method of. forming the holes in the board. to. impartthereto the characteristics above stated. 1

Another object is to provide. a means whereby the facing andba-cking sheetsof. the boardmay be. punctured with holes of. difierent sizes. with the. hole in the backing sheet smaller than. that in the facing sheet and whereby the-hardened plastic composition interposed. between. the sheets will be ruptured and removed in suchfashionas to form; atapered hole through the composition the larger endv of which. is presented to the small opening inthe backing sheet.

"The invention. and the mode of carrying: it into: effect is depicted in the accompanying drawing, in-WhichZ .1 i

Fig. 1 is a view" in front elevation: ofv a fra mentaryportion of a slab. of the lath board;

.. Fig. 2. is an. enlarged detail insectiontakeniorn the line 2-2 of Fig. l showingthe formation of. theplaster receivingholes;

Fig. 3 is a viewsimilarto that shown injFig". 2;

Fig. 5- is a view" si e the parts as positioned iripunching theboardt Fig: 6 is a detail in: section depicting the holes a s'initiallyformed on completion of the punching operation-shown in- Fig; 5 wherein the margin of the hole inthe backing sheet is extended outwardly; e

Fig. 7 is a view similar tothat ofFig. 6 showing the-margin of the hole in the backing sheet pressed so that it extends substantially flush with the-latter:

Referring to the drawing more specifically, A

indicates generally a sheet of'lath-board compris ing" a composition body .IB" interposedj between; paper surfacing" sheets includinga facingsheet I l and a hacking sheet l2as is common in compo;-

s'ition wall board construction. The board A is;

formed with a series of holes B to receive pertime of'a' coat of plaster'C applied to the lath board when the latter-is, assembled in surfacing walls and ceilings. Heretoforeit has been;a:common practice to punch holes through the board of. equal. diameter. throughout.

. "The composition body H1 is. ordinarily formed Fig. 4 is" a view insection, partly in elevation-,-

of a. fragmentary portion of a mechanism for punching and. forming the holes in. the lath boardwith, the. parts shown in position preliminary to punchingthe board;

of a mixture of gypsum. and sawdust and; is ap-i pliedin' awet plastic, state to the. backing sheet a layer: ofrequisite thickness to which layer: the: facing sheet is applied resulting in a panel;

which issu'bseduentlydried and perforated; j i

In carrying out-the present inventiontheholes;

ends ofthe filler thereof opening through the facing sheet l"l while the larger ends thereof open. partly through the backing sheet l2. The side walls. ofithe holesBthusdiverge outwardly from. the front of the board which arrangement perinit's of ready passage'ofportionsof the'plasterq when. thelatter is applied in a plastic state to the-surface; of the board. In order toj preventthe. too free flow of plaster through the holesB to; theback of the board and which would resultirr considerable waste of plaster,the enlarged, ends ofthe holes. B are at least partly covered. as by: portionsj I14, of." the backing sheet. l2. protruding. inwardly from the margins of the enlarged ends of the holes; the portions M'havingfa perforation l hthereinto preventthe entrapment of 1 air in: thehole B on applying plaster thereto and to perinit a. portion or the plaster to pass through. the hole B to the back of. the board as shown at l- 5 in- Fig; 3 and effect a bond with the backing sheet 12' as indicated. The portion 14 of. the. backing sheet thusservesto retardfthe flow of plaster into andjthrough the hoIesBsuch as toi.

insure filling of the holes with the plaster and thus effect a dove-tailed or key bond between the lath board and the portions of the plaster extended into the holes B.

While various means and methods may be employed in forming the holes B including perforating the sheets II and I2 and removing portions of the plaster composition of the board to form the tapered hole, such as by initially punching the board to form holes therein of the size of the perforation l5 and thereafter enlarging the hole in the facing sheet and reaming the walls of the holes in the plaster composition to form the holes with the requisite taper. I have here shown a means and method of ccomplishing the purpose in a single operation, The means shown v embodies a bed plate Hi from the upper faceof which projects an open ended tubular combined displaced is forced downwardly into the open upper end of the tubular punch and die members I! which are then in process of penetrating the sheet I|. As the press l3 continues to move [downward the abutment rings 25 are brought to punch and die I! the lower end of which opens to the underside of the bed plate |6 through an aperture ill in the latter, and the upper end of which is formed with an annular cutting edge I 9 having a serrated contours I Superimposed abovethe bed plate I6 is a ver-- tically movable stripper plate supported on springs 2| interposed between'the bed plate and the stripper plate. An opening 22 is formed in the stripper plate to loosely receive the upper end of the punch and die member l1. Arranged above the stripper plate is avertically movable press 23 on which iscarried a downwardly extending punch 24 adapted to be advanced into the open upper end of the tubular member l1 and which punch is designed to penetrate the lath board A superimposed on the stripper plate 20 to punch the hole IS in the backing sheet l2. Surrounding the punch 24 and carried by the press 23 is an annular abutment member 25 the lower margin of which is spaced upwardly and outwardly from the lower end of the punch 24'; the member 25 being tubular and having its inner periphery spaced from the punch 24. The upper end of the member 25 leads to an opening 26 in the press 23. I

The mechanism above described is designed to carry out my particular method of forming the holes B which consists in punching the facing. sheet H and the backing sheet |2 with opposed holes of different diameters and with the larger hole formed in the facing sheet and the smaller hole formed in the backing sheet and at the same time punching the plaster body I!) with holes of the diameter of that formed in the facing sheet and in a fashion 'to rupture the plaster around the hole being punched in such fashion that on removal .of the ruptured plaster from the hole 4 members I! as shown in Fig. 4. The press 23 is then depressed ,by suitable mechanism (not shown) whereby the punches 24 will be initially brought into contact with the upper face of the panel and on continued downward movement of the press the punches 24 will act to shove the lath panel and the stripper plate downwardly in opposition to the springs 2| until the underside of thepanel is broughtinto contact with the sharp bear on the panel of lath board as indicated in dotted lines so as to exert increased downward pressure on the panel such as to cause the cutting edges l9 to penetrate the facing sheet H and puncture holes through the composition IU of larger diameter than those previously formed by the punches 24. The panel is thus advanced until the upper ends of the punch and die members I! protrude above the upper surface of the panel; the cutting edges of the members then outwardly pressing the marginal portions of the holes |5 previously punched in the sheet |2 as shown in Fig. 5. Forcing of the panel downward over the upper ends of the members I! by the abutment rings 25 hearing on the upper face of the panel in spaced relation and concentric with the upper ends of the members I! effects rupturing of the dry composition along the walls of the hole formed by the members IT. This rupturing occurs progressively outward from the lower to the upper surface of the composition between the sheets I and I2; the ruptured portion being granular and powder-like as indicated at E in Fig. 5. A portion of the material removed from the panel by the punching operation will be passed downwardly through the tubular members I! while other portions will be directed upwardly into the annular abutment member 25.

After completion of the punching operation the press 23 is elevated to its initial position whereupon the stripper plate will move upward under the. urge of the springs 2| and thereby elevate the panel clear of the members H. The granular particles E and such other broken or powdered portions of the dry composition In as may have accumulated on the upper surface of the panel and in the members I! and 25 are removed as by means of a blower.

The holes in the panel will then be cleaned of loose particles and will appear substantially as shown in Fig. 6 with the margins M of the holes |5 in the backing sheet extended outwardly, which margins are then pressed inwardly to extend substantially flush with the backing sheet as by passing the panel between rollers.

While I have shown and described a specific embodiment of my'invention I' do not limit myself to the exact details of construction set forth, and the invention embraces such changes, modifications and equivalents of the parts and their formation and arrangement as come within the purview of the appended claims.

. I claim:

l. The method of forming a composition lath board I with diverging plaster-receiving holes therethrough consisting in simultaneously punching holes in the board from opposite sides thereof with one of the holes of larger diameter than the other and rupturing the composition of the ing portion of the holes in the composition body board progressively outward from one side thereof to the other in the operation of punching the larger hole and removing theruptured portion of the composition.

2; The method of forming plaster-receiving recesses in a lath board embodying a plaster composition body'interposed between a facing sheet anda backing sheet, consisting in punching small holes in the backing sheet and into the contiguous portion of the composition body, then punching larger holes in the facing sheet opposite the smaller holes and through the composition body,

rupturing the walls of the larger holes in the composition body progressively outward from one side thereof to the other during the punching operations, and'effecting removal of the ruptured portions of the composition body.

3. The method of forming plaster receiving re cesses in a composition board embodying a plaster composition body interposed between fibrous sheets consisting in punching opposed holes in.

opposite sides thereof and coincidentally enlargrelative to the holes in the fibrous sheets. L

5. The method of forming plaster receiving holes in a lath board embodying a composition r body interposed between a facing sheet and a backing sheet, consisting in inwardly punching a series of opposed holes in said sheets andatthe same time removing portions of thecomposition body between said holes to form holes extendin therethrough between the opposed holes in the sheets.

6. The method of forming plaster receiving holes in a lath board embodying a composition body interposed between a facing sheet and a backing sheet, consisting in inwardly punching a series of opposed holesin said sheets and at the same time removing portions of the composition the composition body relative to the holesin the body betweensaid holes to form holes extending therethrough between the opposed holes in the sheets, and coincidentally enlarging the hole in facing and backing.

7. The method. of forming plaster receiving holes in .a lath board embodying a composition body interposed between a facing sheet and a backin sheet, consisting in inwardly punching a series of opposed holes in said sheets and at the same time removing portions of the composition body between said holes to form hole's extending therethrough between the opposed holes in the sheets,

and coincidentally enlarging the holes in the composition body relative to the holes in the facing and backing sheets, and extruding the margins of the holes in the backing sheet relative to the adjacent holes in the composition body.

GEORGE A. BU 

